Anti-friction guide



Feb. 23, 1960 R. F. MACK E'rAL ANTI-FRICTION GUIDE Filed Feb. 7. 1957INVENTOR5 `C j( BY "MJU ATTORNEY5 United States Patent M' 2,926,001ANTI-FRICTION GUIDE Richard F. Mack, Albany, and John D. Smith, Selkirk,N.Y., asslgnors to Anti-Corrosive Metal Products Co., Inc., Schodack,N.Y., a corporation of New York Application February 7, 1957, Serial No.638,786 12 Claims. (Cl. 254-190) This invention relates to ananti-friction guide and more particularly to a guide for a cable or wirewhich may be used for control purposes.

Push-pull cables of the Bowden wire type are widely used in remotecontrol. For example, such cables are employed in automobiles forkreleasing the hood latch and for controlling the heater. In someapplications of the push-pull control cable, it is found necessary tobend the cable around one or more curves in order to span the distancebetween the controlling and controlled elements along a convenient path.The axially movable control wires of the cables of the prior art arecommonly encased in an outer sleeve or sheath that has substantiallymore lateral resistance to bending than vthe Wire, so that the wire willnot buckle or kink when compressional forces are exerted on it. Cablesthus constructed work well when the path between the controlling andcontrolled elei ments is substantially straight, but when the cable isbent around one or more curves, particularly fairly sharp curves, theeffort required to move the wire along its axis greatly increasesbecause of the frictional forces applied to the wire at the bends. Thegreater the number of bends and the sharper the curvature of the bends,the greater the force required to move the wire. Increasing theclearance between the axially movable wire and its sheath does notvsolve the problem, because when the wire is placed in compression, itis forced against the outside curvature of -the sheath, and when it isplaced in tension, it is forced against the inside curvature of thesheath. The frictional forces are thus not materially reduced; moreover,increasing the clearance between the wire and the sheath allows the wireto buckle and kink under the influence of substantial axial loads.

Because of the foregoing diilculties it has heretofore been necessary toavoid substantial bending of push-pull control cables, thereby making itnecessary for the cable to follow Ian inconvenient path in many cases,lor preventing the use of push-pull cables Where curves in the cableswould be necessary. The present invention obviates the foregoingproblems by providing a unique cable guide.

`It is accordingly a principal object o-f the invention to provide ananti-friction guide which overcomes the foregoing failings of the priorart.

Another object of the invention is to provide a cable guide having thedesired characteristics and yet which is simple and economical tomanufacture.

A further object of the invention is to provide a cable guide which maybe adjusted to many different coniigurations.

An additional object of the invention is to provide a l cable guide ofthe aforesaid type which employs unique bearing units.

A still further object of the invention is to; provide a cable guide ofthe aforesaid type which includes means for receiving and gripping thesheath of the axially movable wire.

These and other objects of the invention will become more readilyapparent upon consideration of the follow- 2,926,001l Patented Feb. 23,1960 'of the invention;

Figure 3 is an elevation view of the device of Figure 2, shown with anouter covering removed;

Figure 4 is -a plan view of the device of Figure 2 as it appears whencurved and illustrating in more detail the connection of the cable tothe cable guide; and

Figure 5 is a transverse sectional view taken along line 5-5 in Figure2.

Briey stated, the invention comprises a pair of flexible strips betweenwhich a plurality of bearing units are mounted. The bearing units arefixed at one end thereof to one of the strips and are movable withrespect to the other strip. At least one end of one of the strips isadjustable longitudinally with respect yto the other strip and isarranged to be fixed with respect to the other strip to maintain theguide in a predetermined curved configuration. The strips are joined byend pieces, at least one of which is arranged to receive the sheath ofthe cable.

Figure l of the drawing illustrates the use of a pushpull cable 10 incontrolling a power boat 12, as more fully described in anotherapplication of one of the applicants herein, entitled Remote ControlSystem for Power Boat. The boat may be of the outboard motor type andmay have a motor 14 and a steering wheel 16. Control cables of the typeto be described may be used to adjust the orientation of the outboardmotor 14 in response to movement of the steering wheel. In order toprovide a convenient, unobtrusive path for the control cable 10, it isnecessary to provide at least two bends in the cable, as indicated at 18and 20. It is at these bends that the cable guide 22 of the invention isemployed.

Referring to Figure 2, each cable guide in the preferred form comprisesa pair of resilient strips 24, 26, which may be formed of spring steelor other suitable material. The strips are joined in substantiallyparallel relationship by a pair of end pieces or blocks 28, 30 asdescribed herenafter. Each block has a central passage 32 for guidingthe axially movable wire 34 of the control cable 10.

The control cable may assume many different forms, but the axiallymovable Wire 34 commonly has a solid core encased in a helically woundstrip. The axially movable wire thus constituted is commonly guided inan outer metallic sheath 36, which may be formed of helically woundwires. The inner and outer members of the cable may then be encasedwithin a tubular covering (not shown) of rubber, plastic, or similarmaterial. The ends of the control cable are conventionally provided withsuitable fittings for coupling the cable to the controlling andcontrolled elements.

Bach of the end pieces 28, 30 may be provided with means for receivingand gripping the sheath or stationary member 36 of the control cable. Asshown in Figure 4, an exemplary end piece 28 has an enlarged bore 38,for receiving a pair of concentric sleeves, 40, 42, the inner surface ofsleeve 40 and the outer surface of sleeve 42 converging inwardly of thebore. The sleeve 40 and the sheath 36 are formed of a hard material,such as steel, while the sleeve 42 is formed of a relatively softmaterial, such as aluminum. End piece 28 may also be provided With awasher 44 that is arranged to be secured to the end piece as by machinescrews 46, and through which the cable passes.

When the cable guide of the invention is assembled with a cable of thetype described, the outer sheath 36 of the cable is terminated or cutback so that the naked inner member 34 passes into the cable guidebeyond the end piece 28. Sleeve 42 is then slipped over sheath 36, andSleeve 40 is slipped into bore 38. The sheath is then gripped justbeyond sleeve 42 by a tool or clamp, and the end piece, which is not yetattached to strips 24, 26, is hammered onto the sheath, forcing sleeve42 and the end of thesheath into sleeve 40. Washer 44, which may havebeen slipped onto the cable previously, is then se cured to the endpiece, preventing any possibility of dislodging the cable. Thecompression of the soft sleeve 42 between sleeve 4t) and sheath 36securely swages the cable to the end piece. Further details of the cableholder may be found in the afore-mentioned companion application, butthe use of the particular sheath receiving and holding device is notessential to the guide construction of the invention, and other types ofsuch devices may be employed. One of the end pieces may be constructedwithout the sheath holding device, for installations in which thecorresponding end of the cable guide is close to the controlling orcontrolled element and wherein the inner or axially movable member ofthe cable is coupled directly to such element. Moreover, in someinstances the cable guide may be utilized in conjunction with a cablewhich does not have an outer sheath, such applications of the inventionmaking the use of a sheath holding device obviously unnecessary.

At least one end of one of the strips 24, 26 is arranged to beadjustable longitudinally with respect to the other strip and to befixed in Selected positions. In the form shown, both ends of strip 26are provided with slots 48 (Figure 3) which may reciprocate with respectto machine screws 50, which fix the strip ends to the respective endpieces 28, 30 when the screws are threaded tightly into the end pieces.-In the form shown, strip 24 is xed to the respective end pieces bymachine screws 52.

In Figure 2 the strips are shown straight, and screws 50 are located atthe inner ends of the associated slots 48. If the screws 50 areloosened, the strips may be curved as shown in Figure 4, strip 24forming the inner and strip 26 the outer curvature. The screws may thenbe tightened to retain the curved configuration of the guide. It will beobserved that in the bending of the guide, the ends of strip 26 movelongitudinally relative to the strip 24 and the end pieces 28 and 30,screws 50 sliding along slots 48. If screws 50 are loosened again, theguide may be allowed to return to its original straight configuration byvirtue of the naturalresiliency of the strips 24 and 26.

Mounted transversely between strips 24 and 26 are a plurality of spacedbearing units 54. These units are arranged in succession, and each unitmay comprise a rectangular yoke 56 tixed at one end to strip 24, as byrivets 5S or machine screws. The opposite ends of the yokes are notsecured to the strip 26, but instead are movable with respect thereto.Thus, the yokes, which are substantially parallel when the guide isstraight, as shown in Figure 2, may diverage or fan out when the guideis curved, as shown in Figure 4, clearance being provided between strip26 and the yokes for this purpose.

Each yoke constitutes a bearing support member for bearing elementswhich, in the form shown, are constituted by roller bearings 60. Eachyoke may support a pair of such bearings arranged to rotate about axestransverse to the yokes on pins 62 iixed to the yokes. The bearingsurfaces are contoured as shown so thatthe opposed surfaces of each pairof bearings 60 form a substantially circular cross-section. Thecurvature and spacing of the bearings is chosen in accordance with thediameter of the wire 34 that is to be guided. The bearing elements maybe formed of nylon or other suitable material.

lf both ends ot strip 26 are to be adjusted with respect to the endpieces 2S and 30, an odd number of `hearing units may be employed, andthe central unit of the series of units may be fixed to strip 26 as wellas to strip 24.

In some instances, both strips may be iixed to one end piece, and theadjustment described above may be restricted to the other end piece. Ifa reversely curved guide is desired, some of the bearing units may beiixed to one of the strips and other bearing units to the other strip,with both strips being adjustable. Reverse curvature may also beprovided by using two guides in sequence.

It will thus be apparent that with the use of the invention, thepush-pull member of the control cable is supported at spaced pointsalong the length of a curve and. that rotary bearings are provided atthese points to reduce greatly the frictional drag exerted on thepushpull member. With the use of the invention, a substantial number ofcurves may be employed without unduly increasing the force which must beexerted to move the control cable.

A suicient number of bearing units is employed inthe guide to preventany tendency of the push-pull member to buckle or kink. In order toprotect the bearing units, the entire guide structure described may becovered by a Flexible boot 64 (Figure 2) formed of plastic, rubber, orother suitable material. The boot may be accordion pleated, as shown, toincrease its exibility.

While there has been described and shown what is now believed to be apreferred form of the invention, it will be apparent to those skilled inthe art that changes may be made in this form without departing from theprinciples and spirit of the invention, the scope of which is defined inthe appended claims. Accordingly, this form is to be consideredillustrative rather than restrictive of the invention and thosemodifications which come within the meaning and range of equivalency ofthe claims are intended to be included therein.

We claim:

1. A cable guide comprising a pair of substantially parallel flexiblestrips, means for adjusting the position of at least one end of one ofsaid strips with respect to the corresponding end of the other strip andfor xing said position, whereby said strips may be curved, and bearingmeans mounted between said strips for guiding the movable member of acable between said strips.

2. The cable guide of claim l, wherein a pair of end pieces joins thecorresponding ends of said strips, and wherein said adjusting meanscomprises means for sliding said one end with respect to thecorresponding end piece.

3. The cable guide of claim l, wherein said bearing means comprises aplurality of bearing units iixed to one of said strips but movable alongthe other strip.

4. The cable guide of claim 3, wherein each of said units has a bearingelement supporting member transverse to said strips, each member beingfixed at one end thereof to one of said strips.

5 The cable guide of claim 4, wherein each supporting member has a pairof opposed rollers rotatable about axes transverse thereto.

6. The cable guide of claim 1, wherein said strips are surrounded by ailexible covering.

7. The cable guide of claim l, further including means connected to atleast one end of said strips for receiving the end of a sleeve in whichsaid movable member moves beyond the guide.

8. A cable guide comprising a flexible bearingsupport ing strip, aplurality of bearing units xed in succession along said strip, a pair ofmeans secured, one to each end of said strip, and fastening meanscooperating with each of said pair of means for holding said strip incurved configuration.

9. The combination of claim 8 wherein each of said pair of means isprovided with a cable-guiding channel for guiding the cable into thebearing units, said channels being axially aligned with the two cndmostof said bearing units respectively.

l0. The cable guide of claim 8, wherein each of said bearing units has arotary bearing element arranged to rotate about an axis transverse tothe associated member.

11. A cable guide comprising a flexible bearing-supporting strip, and aplurality of bearing units xed in succession along said strip andincluding a second strip having at least one end thereof adjustablelongitudinally 5 with respect to the lirst-mentioned strip, and meansfor fixing the ends of the second strip With respect to theiirstmentioned strip to hold said strips in a selected curvedconguration.

12. The cable guide of claim 11, wherein said bearing units are xed atone end thereof to therst-mentioned strip and are movable with respectto the second strip so that said units may diverge when the strips arecurved.

References Cited in the file of this patent UNITED STATES PATENTS2,442,817 Lyle June 8, 1948

